Hypoxemic Episodes of Patients in a Postanesthesia Care Unit: Results

Hypoxemic Episodes of Patients in a Postanesthesia Care Unit: ResultsDuring this study of 100 postoperative patients, a total of 472 detected desaturations occurred within the set of parameters of Sa02 ^92 percent for longer than 30 s. However, on review of the hard-copy printout of saturation, pulse rate, and pulse intensity, it was apparent that most of these episodes could not be reliably interpreted as true hypoxemic episodes because of the loss of good delineation of the puke intensity by the monitor. This resulted in exclusion of many potential data points, but it increased the specificity of the results. A total of 68 episodes of desaturation occurred that were viewed as valid.
On postoperative admission to the PAR, 15 percent of patients had an Sa02 less than 92 percent. Hypoxemia on PAR admission was more likely in patients who had general, rather than regional, anesthesia (p = 0.03), who were older (p = 0.03), of heavier weight (p = 0.0001), of a higher American Society of Anesthesiologists (ASA) class (p = 0.0006), or had received greater volumes of intravenous fluids during surgery (p = 0.001), particularly greater than 1,500 ml. All patients responded to oxygen administration with Sa02 increases above 97 percent.
After recovery to a Sa02 of ^97 percent during oxygen administration, 25 percent of all postoperative patients decreased their SaO£ to less than 92 percent at least once during their PAR stay. This initial desaturation was to 86.7 ±4.6 percent, ranging from 72 to 91 percent, and occurred 32 ±54 min following admission (all values are given as mean ± standard deviation). Initial desaturations occurred as late as 170 min after admission. The initial desaturations lasted 5.2 ±2.6 min (range, 0.5 to 60 min). Desaturations occurring after admission were more likely in patients who had longer surgical and anesthesia times (p = 0.002), peripheral rather than abdominal or thoracic surgery (p = 0.02), who had received greater amounts of intraoperative intravenous fluids (p = 0.001), or had decreased Sa02 on PAR admission (p = 0.04). Primary Blastomycosis
The duration of desaturations were longer in female subjects (p = 0.05), patients of greater weight (p = 0.04), and again in those who received greater volumes of intravenous fluids (p = 0.02).
A positive patient history for cigarette smoking was not found to be related to the incidence of desaturations. Narcotic dosage received intraoperatively, in the PAR, and total dosage were also not significant influences on desaturation tendencies.

This entry was posted in Hypoxemic Episodes and tagged abdominal surgery, anesthesia, hypoxemia, oxygen saturation, postoperative hypoxemia.